Oc12

KFJB No. 6 (SiW 178/1868) had a long life. Later kkStB 24.01, it finally became ČSD 233.001 and remained in use until 1927. Probably this is a factory photo of the engine with its original boiler. Source: www.commons.wikimedia.org.

Side drawing of class 233.0. Source: EZ vol. 1.

Among steam locomotives taken over by Polish railways from Austrian kaiserlich-königliche Staatsbahnen (kkStB) were several light passenger engines with the 1-2-0 axle arrangement. They belonged to various types and were originally built for various private and local railways. Within the framework of the new PKP designation system, introduced in 1925, they were assigned class designations Oc11 through 17. However, this re-numeration was in fact only formal, as these old and obsolete engines were withdrawn before the new system came into use. Which designation was allocated to which individual type is still subject to dispute, as original documentation is not available. Information on this subject that appears in references is based on indirect evidence and, at best, should be considered questionable. We may only hope that someday more reliable source shall be revealed.

This refers also to two locomotives from a batch of thirty-two classed AF I, built for the Kaiser-Franz-Josephs-Bahn (KFJB) between 1868 and 1872 by Sigl at the company’s factories in Vienna (SiW) and Neustadt (SiN). These were the very first locomotives for this railway, running between Vienna and Prague, construction of which began after the war with Prussia of 1866. Prototype (SiW 173/1868) was named ‘Johann Adolph’ and was the sole locomotive of this type to be given an individual name. They were numbered 1 through 32. KFJB was nationalized in May 1884 and these engines became kkStB 2401 through 2432, later 24.01 through 32 (apart from 2419, which was written off in 1900). Between 1886 and 1895 they were re-boilered, with 167 flues instead of 156 and steam pressure increased from 9 to 10 bar.

Between 1909 and 1917 as many as eighteen of these already obsolete locomotives were withdrawn from use. 24.01 perished in Russia. Czechoslovakian state railways ČSD received ten examples, but only three survived in use long enough to be given new designations. They in fact saw little service and some were used exclusively as stationary boilers at various railway depots. They were classed 233.0 and the last one, 233.001 (ex 24.06, SiW 178/1869) was withdrawn in July 1927. The remaining two examples, 24.28 (SiN 1048/1870) and 24.31 (SiN 1468/1872) were handed over to PKP, but both were written off before 1927. Possibly they were assigned new class designation Oc12 (according to www.de.wikipedia.org and LAÖ), but this is confirmed neither by LP nor by KT. This question remains open and requires further study. No locomotive of this type has been preserved.

Main technical data^*)

No.	Parameter	Unit	Value
1.	Years of manufacture	-	1868 – 1872
2.	Total built / used in Poland	-	32 / 2
3.	Tender class	-
4.	Axle arrangement	-	1-2-0
5.	Design maximum speed	km/h	60
6.	Cylinder bore	mm	2 X 408
7.	Piston stroke	mm	632
8.	Engine rating	kW/hp
9.	Tractive effort	kG
10.	Boiler pressure	MPa	1.02
11.	Grate dimensions	m X m	1.63 m^2
12.	Firebox heating surface	m^2	7.9
13.	Distance between tube plates	mm	4 130
14.	Number of flue tubes	-	167
15.	Heating surface of flue tubes	m^2	110.5
16.	Number of smoke tubes	-	-
17.	Heating surface of smoke tubes	m^2	-
18.	Evaporating surface, total	m^2	118.4
19.	Superheater heating surface	m^2	-
20.	Diameter of drivers	mm	1 574
21.	Diameter of idlers front/rear	mm	1 180 / -
22.	Total weight, empty	kg	30 700
23.	Total weight, working order	kg	34 600
24.	Weight on drivers, working order	kg	24 600
25.	Weight with tender, empty	kg
26.	Weight with tender, working order	kg
27.	Maximum axle load	T
28.	Axle base (with tender)	mm	10 560
29.	Overall length (with tender)	mm	14 947
30.	Brake type	-

^*) All data after re-boilering.

References and acknowledgments

- LP, KT vol. 1, EZ vol. 1, LAÖ;

- www.de.wikipedia.org.